What is the optical configuration of a typical gamma-ray telescope?

0 votes

A single large slab of material that totally absorbs the individual gamma rays that encounter it.
A series of concentric tapered tubular mirrors that the gammma rays strike at shallow grazing incidence angles.
A spherical primary mirror that directs the gamma rays toward a specially shaped secondary mirror, which bounces the gamma rays back down through a hole in the primary mirror to a detector.
Special lenses made of fluorite and/or other minerals that transmit gamma rays efficiently.
A parabolic primary mirror that directs the gamma rays toward an elliptical secondary mirror, which bounces the gamma rays out of the incoming light path to a detector.